Plug coupling for use in combination with electric switches



Oct. 3, 1933. J, TUCKER 1,928,916

PLUG COUPLING FOR USE IN COMBINATION WITH ELECTRIC SWITCHES Filed June 4, 1931 2 Sheets-Sheet l (A LWMN, 4 @15 7? Oct. 3, J B. E

PLUG COUPLING FOR USE IN COMBINATION WITH ELECTRIC SWITCHES Filed June 4, 1931 2 Sheets-Sheet 2 Patented Oct. 3, 1933 PATENT OFFICE PLUG COUPLING FOR USE IN COMBINATION- WITH ELECTRIC SWITCHES fJohn Bristow Tucker, Tyseley, Birmingham,

England .Application June 4, 1931, Serial No. 542,045, and in Great Britain July 5, 1930 6 Claims. (01. 200-50) in which provision is made for preventing the withdrawal of the plug except when the switch is in the off position.

The present'invention has for its object the provision of an improved plug coupling of the '10 aforesaid kind, which is simple in construction and efficient in operation, and'which is characterized by the utilization of plug pin means of .well-known formation, that is to say, a plug pin 'or plug pins of plain cylindrical formation either longitudinally" slit or not, as may be desired, or a plug pin orplug pins of flat or blade formation.

A plug coupling is described in my prior Patent No. 1,886,137, granted Nov. 1, 1932, but where- "as-in that specification a plain frictional clutching of the pin was obtained, in the present invention a wedging action is involved in such a manner that the greater the pull imparted to the plug (when theswitch is closed) the more effectively is the wedging operation appliedfor retentive purposes.

' According to the present invention there is provided a plug coupling for use in combination with an electric switch comprising a socket for the reception of the plug, which socket incorporates a roller, ball, block or like device operatively associated with the switch mechanism, in such a manner that when the switch is in the off position the plug is capable of ready insertion, whereas when the switch is closed the roller or like device is adapted to operate in combination with an inclined face to wedge or clinch the plug within its socket against withdrawal.

The wedging operation of the roller, ball, block or like device is advantageously'assisted by means of an appropriately incorporated spring.

Conveniently the socket is of duplex formation involving an inner slotted socket part proper and an outer shell provided with inclined faces for the co-operation of twin rollers which are normally urged towards the slots in the inner socket (for engaging the plug pin) by a springcontrolled plate or like device operatively connected to the tumbler switch mechanism.

The invention further resides in the details of construction and modifications hereinafter described.

In order that this invention may be clearly understood and readilyfcarried into practice, reference may be had to the appended explanatory sheets of drawings, upon which:

aperture b being screw-threaded to engage the Figure 1 illustrates more or less diagrammati cally a plug-and-socket mechanism associated with a switch according to the present invention.

Figure 2 is a vertical sectional elevation on the line 2-2 of Figure l, the switch having however been manipulated (to the closed position) to bring about the wedging of the plug against withdrawal.

Figure 3 illustrates in elevation one of the rollers hereinafter referred to.

Figure 4 illustrates more or less diagrammatically a blade-and-socket mechanism associated with a switch according to the present invention.

Figure 5 illustrates the blade-and-socket mechanism in vertical sectional elevation, the blade being in the clinched or wedged condition.

Figure .6 is an end elevation of the mechanism shown in Figure 5.

In a convenient embodiment of the present invention, as shown by the drawings, a is the inner socket part proper which comprises a tube having diametrically opposed slots a and a screw-threaded upper portion a b is a frustroconical shell mountedaround the socket a, its

threaded part a of the socket a. c is a plate which maintains the parts at their lower extremities. d are twin rollers, more particularly illustrated in Figure 3, from which it is to be noted that each roller involves two concave faces d each of which is advantageously serrated or roughened. It is to be noted that the rollers d are adapted to operate upon inclined faces b in the upper part of the frustro-conical shell, and their axial displacement is prevented by means of wings I) integral with the shell b. e is a plate slidably mounted within the shell and perforated for the reception of the socket a and also of course its associate plug pin f which it is to be noted is of plain or normal character, and which may or may not have a slot or slots f as illustrated. Mounted between the plate e and the base 0 is a helical compression spring 5 which normally urges the plate upwardly and consequently rolls the rollers along the inclined faces b so that they efiectively co-operate with the slots a in the socket a. it illustrates the switch mechanism. h is an extension of the pivot pin rigidly held by the finger manipulative lever W. 71. is a cam upon the extension h Manipulation of the lever k rotates the pin h and causes the cam n to operatively displace the plate e. Briefly when the switch is open the plate e is pressed downwardly against the operation of its spring 9 so that the rollers move into 110 the wider portions of the chamber, and the plug pin f can be readily inserted, whereas when the switch is closed the cam b releases the plate e and the rollers d are raised and brought into effective wedging engagement with the plug pin 1 so as to maintain same against being withdrawn.

In the modification illustrated in the Figures 4, 5 and 6, instead of the plug pin being of circular formation a plug pin 1 of flat section may be utilized. The socket comprises two vertical blades 1' connected to and held by the terminal screw 2' between which blades i the flat pin f is adapted to be thrust. 7' is the shell adapted to locate the parts, said shell being provided with an inclined inner bearing face 7' (more particularly shown in Figure ,5). k is the roller which is serrated as illustrated, and is adapted to protrude through an aperture in one of the blades "5 so as to be operatively engaged with the flat pin f Z is a small frame or bracket adapted to fulcrum at the point 7' and be pivotally operated as for instance by the cam in mounted on a spindle h associated with the switch mechanism h h. The roller k is provided with trunnions k operating in slots in the bracket Z, and the said bracket 1 is normally urged upwardly by means of a plate m. placed under the influence of a coil springm In operation when the switch is open, the cam h depresses the bracket 1 so as to compress the spring m and allow the roller k to fall so as to permit of the ready withdrawal of the flat pin it. When the switch is closed however the bracket Z is released by the scam b so that the compression spring m elevates the bracket and allows the roller to operate upon the inclined face 7' to effectively bind the flat pin between that face and the opposed blade 1' within the shell 7'.

What I claim as my invention, and desire to secure by Letters Patent, is:

1; In combination, an electric switch, a plug socket, a shell element .havinga face inclined relative to the axis of the plug socket, a member mounted for movement against said face so as to cooperate therewith to exert a wedging action against a plug disposed within said socket, a spring constantly tending to move said member in a direction to produce a wedging action against said face and being operable to so move said member when the switch is closed, and means whereby opening of the switch is necessary to permit movement of said member from a plug securing position to a plug releasing position.

2. In combination, an electric switch, a plug socket, a shell element having a face inclined relative to the axis of the plug socket, a member mounted for movement against said face so as to cooperate therewith to exert a wedging action against a plug disposed within said socket, a spring constantly tending to move said member in a direction to produce a wedging action against said face, and a connection between said switch and said member whereby opening of the switch moves said member to a restrained position and whereby closing of the switch releases said member for plug securing wedging movement by said spring.

3. The combination as set forth in claim 1 in which the wedging member is constructed to roll against the inclined face of the shell element.

4. The combination as set forth in claim 2 in which a bracket supports the wedging member and in which the connection between the switch and the wedging member comprises a switch rotatable shaft having a cam cooperating with said bracket.

5. In combination with an electric switch, a plug coupling comprising a socket adapted to receive a plug, a part having an inclined face in spaced relation to said socket, a loose member arranged to coact with said inclined face for producing a wedging action on the plug, and an operable connection intermediate the switch and said member whereby the latter is rendered effective to wedge theplug within said socket when the switch is closed and is actuated to release the plug, when the switch is opened.

6. In combination with an electric switch, a plug coupling comprising a socket adapted to receive a plug, a part having an inclined face in spaced relation to said socket, a loose member arranged to coact with said inclined face for producing a wedging action on the plug, means tending to move said member along said inclined face to its wedging position, and a means operable by said switch when opened to oppose the action of said last named means thereby causing said loose member to release the plug.

JOHN BRISTOW TUCKER. 

